Good post, Geticus!

I have to impose house rules on myself to stop winning battles so easily on medium battle difficulty. In a half-stack army of 10 units, I permit myself to have only one unit of slingers and only one unit of skirmisher light cavalry. This stops them dominating the battlefield - they can soften up the enemy, but the main part of the work still has to be done by line infantry, swordsmen and spearmen. My main use for slingers is as town garrisons - they are only allowed out to fight nearly rebels.